plymouth: stage2 fix primarily for live

It appeared that plymouthd.conf wasn't set up properly
thus "service plymouth stop" didn't result in anything
meaningful; thanks boyarsh@ for his help figuring this
out again.

features.in/plymouth/stage2/image-scripts.d/10-plymouth

@@ -1,3 +1,9 @@
 #!/bin/sh
 
+CONFIG=/etc/plymouth/plymouthd.conf
+
+if [ -f "$CONFIG" ]; then
+	grep -q '^Theme=' "$CONFIG" || sed -i 's/#\([T\[]\)/\1/' "$CONFIG"
+fi
+
 cp -a /usr/share/plymouth/default-install-duration /var/lib/plymouth/boot-duration